Compilation
Cassia zanzibarensis

VARIATION. C. singueana shows a wide range of variation which is difficult to analyse clearly. It appears that characters such as presence or lack of indumentum, number, size and shape of leaflets and size of flowers are varying to some extent independently. Specimens from a single region often look similar, but may pass by perplexing intermediates into a different variant occupying an adjacent region. Furthermore the same or similar variants may occur in regions widely separated geographically. It seems therefore preferable not to recognize any named infraspecific taxa, but to attempt a general simplified account of what occurs in East Africa.In Uganda forms prevail with comparatively short leaflets about 2–4 cm. long and up to or slightly more than twice as long as wide. Their general shape is elliptic, with their greatest breadth about the middle, but less commonly tendencies to an obovate or slightly ovate shape may be shown. The indumentum on the leaflets varies from densely pubescent to almost glabrous. The inflorescence axes are ± grey-pubescent and the sepals ± so outside.In inland Kenya forms occur similar to those of Uganda, and these extend to the coast. There, however, a rather distinctive variant also occurs, with rather long elliptic leaflets up to 6 cm. in length and usually more than twice as long as broad and the indumentum on the outside of the sepals characteristically dense, conspicuous and yellowish (var. flavescens, see above).This variant also extends along the coast of Tanganyika. A specimen of this variant, Hughes 240, from Tanganyika, Tanga District, Same-Gonja road, has valuable on the bark, which is there stated to be medium-grey, smooth, marked with characteristic broadly obtriangular lenticels 0.6 cm. long, slight vertical ridges and from time to time marked horizontal ones. It is at present uncertain if these characters are shown also by the other variants of C. singueana. Inland in Tanganyika two other principal forms occur, one with densely pubescent short obovate leaflets which is found in Kenya also, and a glabrous one in southwestern Tanganyika (var. glabra, see above) which is scarcely separable from similar but apparently infrequent forms in Kenya and Uganda.